Evolutionary Link between X-ray Pulsars and Millisecond Radio

Pulsars

李向东南京大学天文学系

2009-7-30

Radio Pulsars-Rotation Powered

X-ray Pulsars-Accretion Powered

LMXBsHMXBs

The Recycled Scenario

X-ray pulsars

Spin Periods

Millisecond X-ray Pulsars

Main type Sub-typeObservational examples

Recycled PSR + low-mass comp.(MC≤ 0.45M⊙)

PSR + (He) WDPSR J0437-4715PSR J1640+2224

Mildly recycled PSR + high-mass compact comp.(0.5≤MC/M⊙≤1.4)

1. PSR + NS (double)2. PSR + (ONeMg) WD3. PSR + (CO) WD

1. PSR B1913+162. PSR J1435-61003. PSR J2145-0750

Non-recycled pulsar (CO) WD + PSR PSR B2303+46

Un-evolved companion1. PSR + B-type comp.2. PSR + low-mass MS

comp.

1. PSR B1259-632. PSR B1820-11

Binary Pulsar Population

Binary Pulsar Population

Breton 2009

Stellar Evolution

Stellar Evolution

Evolution of HMXBs• Unstable mass transfer and common

Envelope evolution

Evolution of LMXBs

• Nuclear evolution• Mass and angular momentum loss

Form

ation Channel (1)

Single NS

TZO

TZO

Form

ation Channel (2)

Observations vs. Theories

Deloye 2008

Too long Porb or too small M2?

Black widow pulsars?

Problems with LMXB Evolution

• The formation of LMXBs requires a contrived evolution with– extreme initial mass ratio– ejection of a massive common envelope by a l

ow-mass star– survival as a bound system after the SN

Problems with LMXB Evolution

• Birthrate problem (Kulkarni & Narayan 1988)– NLMXB ~ 100, τLMXB ~ 10^9 yr– NBMSP ~ 10^5, τBMSP ~ 10^9-10^10 yr– NBMSP /τBMSP ~ 10-100 NLMXB /τLMXB

Problems with LMXB Evolution

• Mass and angular momentum loss

Andronov et al. (2001) Lattimer (2007)

Problems with LMXB Evolution

• Luminosity distribution

Podsiadlowski et al. 2002

PSR J1903+0327

• In the Galactic plane

• Ps=2.15 ms

Porb=95 days

• Mpsr~1.74 Msun

• M2~1 Msun

• e = 0.44!